In South Dakota, at a depth of almost one kilometre, the underground LUX-ZEPLIN detector has set a new world record for sensitivity in the search for dark matter, the mysterious substance that makes up more than 80% of the mass of the universe.
Deep underground, at the Sanford Underground Research Facility in South Dakota, an international team of physicists has taken a step forward in unravelling one of the greatest mysteries of the cosmos: the nature of dark matter. The LUX-ZEPLIN (LZ) experiment, considered the world’s most sensitive detector of its kind, has set a new record for accuracy in the search for the invisible substance that makes up more than 80% of the mass of the universe. The research data is published on the Scitechdaily.com website.
The LZ detector is located nearly a mile underground, where it is reliably protected from cosmic radiation and extraneous particles. At its heart are ten tonnes of ultra-pure liquid xenon, capable of capturing the tiniest flashes of light produced by rare collisions between atoms and dark matter particles known as WIMPs (weakly interacting massive particles).
Analysis of data collected over 280 days of observation has allowed us to establish the most stringent constraints to date on the properties of these hypothetical particles. ‘Even if we can’t see dark matter directly yet, we are getting a clearer picture of what it is not,’ said project leader Hugh Lippincott, a physicist at the University of California, Santa Barbara.
To rule out false signals, the researchers use a complex system of data protection and filtering. Inside the facility, multi-layer insulation blocks neutrons and radon, and an original ‘salting’ method is used, which involves adding artificial signals to rule out human error and bias in the analysis.
The LZ project brings together more than 250 scientists from six countries and is supported by the US Department of Energy and international research foundations. Until the experiment is completed in 2028, the detector will continue to collect data for about 1,000 more days. Scientists are already making plans for the future – to develop the next generation XLZD facility, which will be able to search for particles with even greater precision.
Although the ‘great discovery’ has not yet happened, scientists are confident that each new result brings humanity closer to understanding the invisible side of the universe. As the project participants say, ‘even the silence of dark matter is also an answer.’
